Multicriteria Decision-Making Technique for Choosing the Optimal Ammonia Energy Share in an Ammonia-Biodiesel-Fueled Reactivity-Controlled Compression Ignition Engine.

Low-temperature combustion paired with the use of carbon-free ammonia and carbon-neutral biofuels is a novel approach for improving performance, reducing greenhouse gases, and reducing regulated emissions. Reactivity-controlled compression ignition (RCCI), a low-temperature combustion technology, dramatically reduces NOx and smoke emissions compared to traditional engines. Ammonia can be projected as a good transit fuel in the journey toward achieving net zero emissions and cleaner energy. This study examines the impact of ammonia energy premixing fraction (AEPF) (20, 30, 40, and 50%) as a low-reactive fuel (LRF) and algal biodiesel as a high-reactive fuel on the performance and emission characteristics of a single-cylinder, water-cooled 3.5 kW CI engine at a constant speed of 1500 rpm under various loading conditions. The research results indicate that the 40% ammonia share RCCI mode exhibited a reduction in carbon dioxide (CO2) by 14.16%, nitrogen oxide (NOx) by 22.6%, and smoke by 42.1%, with an 11.5% improvement in thermal efficiency compared to the neat biodiesel-fueled conventional engine. Furthermore, the analytical hierarchy process (AHP) will be used in conjunction with the technique for order of preference by similarity to ideal solution (TOPSIS) of multiple criteria decision-making techniques to determine the optimal energy share in the RCCI combustion with the goal of achieving superior thermal efficiency and lower emissions. According to the AHP-TOPSIS study findings, AEPF40 is the best choice for all engine loads.

Experimental Studies to Reduce Usage of Fossil Fuels and Improve Green Fuels by Adopting Hydrogen-Ammonia-Biodiesel as Trinary Fuel for RCCI Engine.

This study investigates the feasibility of hydrogen addition to achieve lower emissions and higher thermal efficiency in an ammonia-biodiesel-fueled reactivity-controlled compression ignition (RCCI) engine. A single-cylinder light-duty water-cooled compression ignition (CI) engine was adapted to run in RCCI combustion with port-injected ammonia and hydrogen as low reactive fuel (LRF) and direct-injected algal biodiesel as high reactive fuel (HRF). In our earlier study, the ammonia substitution ratio (ASR) was optimized as 40%. To optimize fuel and engine settings, hydrogen is added in quantities ranging from 5 to 20% by energy share. The combustion, performance, and emission characteristics were investigated for the trinary fuel operation. The result shows that the 20% hydrogen premixing with 40% ammonia-biodiesel RCCI operation increased the peak cylinder pressure (CP), peak heat release rate (HRR), and cumulative heat release rate (CHRR) by 15.12, 25.15, and 26.68%, respectively. Ignition delay (ID) and combustion duration (CD) were decreased by 15.53 and 11.24%, respectively. The combustion phasing angle was advanced by 4 °CA. The brake thermal efficiency (BTE) was improved by 15.49%, and brake specific energy consumption (BSEC) was reduced by 21.92%. While the nitrogen oxide (NOx) level was significantly increased by about 31.82%, the hydrocarbon (HC), carbon monoxide (CO), smoke, and exhaust gas temperature (EGT) were reduced by 24.53, 28.16, 25.82, and 17.47% as compared to the optimized ASR40% combustion.

Experimental Investigation on the Effect of Graphene Oxide in Higher Alcohol Blends and Optimization of Injection Timing Using an ANN Method.

The use of alternative fuels in diesel engines has become more widespread due to a number of factors, including dwindling petroleum supplies, increasing prices for conventional fossil fuels, and environmental worries about pollutants and greenhouse gas emissions from internal combustion engines. Efficiency and emissions need to be appropriately balanced. Alcohols act as oxygenated fuels similar to octanol, offering a number of benefits over traditional fuels and can boost efficiency, enhance combustion, and reduce air pollution. Therefore, the research aimed to enhance the performance and combustion characteristics of a diesel and octanol blend using graphene oxide (GO) nanoparticles as a fuel additive in a single-cylinder diesel engine while reducing emissions. Research findings will contribute significantly to improving the physical and chemical properties of diesel and octanol blends, thereby mitigating the challenges of limited petroleum reserves and environmental concerns. A range of different blends of diesel and octanol were prepared on a volume/volume basis in proportions of D70OCT30, D60OCT40, and D50OCT50, and then GO was added as a fuel additive to the abovementioned blends in varied proportions (40, 60, and 80 ppm) resulting in nine blends. These blends were analyzed in terms of various performance, combustion, and emission characteristics, and the obtained results helped to shed light on the impact of GO as a fuel additive. The results indicated that the fuel blend D70OCT30GO0.006 yielded the highest values. Furthermore, it is highly imperative that we develop a model that can be used to predict engine behavior and its stability without having to run an engine. For this, a data-driven artificial neural network (ANN) model was developed to predict the optimized injection timing for better combustion and reduced emission. The efficiency and prediction capabilities of the model were compared to the experimental data, which indicated that the ANN model had a better prediction score. The injection timing of the engine was optimized from 21 °CA to 21.5 °CA, which increased the efficiency by 1%. The research findings showed significantly improved physical and chemical properties of the blends, thereby mitigating the challenges of limited petroleum reserves and environmental concerns.

Investigation on Ammonia-Biodiesel Fueled RCCI Combustion Engine Using a Split Injection Strategy.

Advanced combustion concepts in compression ignition are emerging as one of the most promising solutions to reduce nitrogen oxides (NOx) and particle emissions without sacrificing fuel efficiency. Among many advanced combustion concepts, reactive controlled compression ignition (RCCI) can achieve a wider working range. In this study, to implement RCCI operation, ammonia gas is introduced through the manifold as a low-reactive fuel, and biodiesel is injected directly as a high-reactivity fuel with a 40:60 energy ratio. The effect of biodiesel split ratio in a split injection strategy (pre- and main injections) is examined under varied load conditions, and the results are compared with ammonia/biodiesel single injection. Results indicate that the use of the 45% biodiesel split ratio at full load boosts the peak in-cylinder pressure and heat release rate and shifts the peak occurrence toward the top dead center (TDC). An increase in brake thermal efficiency (BTE) to 36.22% and reduced brake specific energy consumption (BSEC) to 8.75 MJ/kWh are 12.33% higher and 19.31% lower than ammonia/biodiesel single injection. Emissions of HC, CO, and smoke opacity were reduced to 50 ppm, 0.098% vol, and 15.6%, which are 34.21, 39.13, and 33.89% lower, while the emission of NOx was increased to 615 ppm, which is 36.06% higher than the single-injection ammonia/biodiesel RCCI combustion.

Effect of Infill Patterns with Machine Learning Techniques on the Tensile Properties of Polylactic Acid-Based Ceramic Materials with Fused Filament Fabrication.

The field of additive manufacturing is quickly evolving from prototyping to manufacturing. Researchers are looking for the best parameters to boost mechanical strength as the demand for three-dimensional (3D) printers grows. The goal of this research is to find the best infill pattern settings for a polylactic acid (PLA)-based ceramic material with a universal testing machine; the impact of significant printing considerations was investigated. An X-ray diffractometer and energy-dispersive X-ray spectroscopy with an attachment of scanning electron microscopy were used to investigate the crystalline structure and microstructure of PLA-based ceramic materials. Tensile testing of PLA-based ceramics using a dog bone specimen was printed with various patterns, as per ASTM D638-10. The cross pattern had a high strength of 16.944 MPa, while the tri-hexagon had a peak intensity of 16.108 MPa. Cross3D and cubic subdivisions have values of 4.802 and 4.803 MPa, respectively. Incorporating the machine learning concepts in this context is to predict the optimal infill pattern for robust strength and other mechanical properties of the PLA-based ceramic model. It helps to rally the precision and efficacy of the procedure by automating the job that would entail substantial physical effort. Implementing the machine learning technique to this work produced the output as cross and tri-hexagon are the efficient ones out of the 13 patterns compared.

Potential Effect of Lemon Peel Oil with Novel Eco-Friendly and Biodegradable Emulsion in Un-Modified Diesel Engine.

The current research work is based on exploring a novel biological fuel source and renewable fuel offered by waste lemon fruit skin. Furthermore, bio-based multi-wall carbon nanotubes (BMWCNTs), emulsion, fossil diesel, and raw lemon peel oil were procured. The single-cylinder diesel engine was evaluated using these potential ingredients in terms of performance, combustion, and emission. Test engine results reveal that the presence of BMWCNT emulsion in the bio-fuel + blend + emulsion blend produced a lower (4.7%) brake thermal efficiency (BTE) and a higher (13.6%) brake-specific energy consumption (BSEC) at peak engine load conditions with diesel. The same test fuel blend possesses an equivalent heat release rate (HRR) and cylinder pressure trends to the diesel fuel blend due to an optimized air/fuel mixture and oxygen supply. Bio-fuel + blend + emulsion achieved step-down reductions of 7.83% carbon monoxide (CO) and 20.68% hydrocarbon (HC) emissions, as well as reductions of 27.7% nitrogen oxide (NOx) and 37.3% smoke emissions at peak engine load with diesel.

Experimental Investigation on the PCCI Engine Fueled by Algal Biodiesel Blend with CuO Nanocatalyst Additive and Optimization of Fuel Combination for Improved Performance and Reduced Emissions at Various Load Conditions by RSM Technique.

Fossil fuel depletion and environmental pollution are paramount problems the world faces. Despite several measures, the transportation industry is still battling to manage these issues. A combined approach of fuel modification for low-temperature combustion with combustion enhancers could offer a breakthrough. Due to their properties and chemical structure, biodiesels have piqued the interest of scientists. Studies have asserted that microalgal biodiesel might be a viable alternative. Premixed charge compression ignition (PCCI) is an easily adoptable promising low-temperature combustion strategy in compression ignition engines. The objective of this study is to identify the optimal blend and catalyst measure for improved performance and reduced emissions. Microalgae biodiesel at various proportions (B10, B20, B30, and B40) was amalgamated with CuO nanocatalyst and tested to arrive at the right concoction of biodiesel with nanoparticles in a 5.2 kW CI engine for different load conditions. The PCCI function warrants that about 20% of the fuel supplied is vaporized for premixing. Finally, the interplay factors of the independent variables of the PCCI engine were then explored by response surface methodology (RSM) to determine the optimal level of desired dependent and independent variables. The RSM experiment findings suggest that the best biodiesel and nanoparticle concoctions at 20%, 40%, 60%, and 80% loads were B20CuO76, B20Cu60, B18CuO61, and B18CuO65, respectively. These findings were experimentally validated.

Performance and emission reduction characteristics of cerium oxide nanoparticle-water emulsion biofuel in diesel engine with modified coated piston.

In the present scenario, the utilization of petroleum fuel is expanding forcefully worldwide in the vitality store and plays a highly hazardous role in the ecological system. Biofuel stands out among the most tenable keys for this issue. The lemongrass oil is used as a biofuel because of low density and viscosity when compared with diesel. The lemongrass oil is extracted by steam distillation process. In the present investigation, partially stabilized zirconium, due to its higher thermal conductivity, is selected as coating material. The top surface of the piston and the inlet and exhaust valves are coated up to the preferred thickness of 500 µm by the plasma spray technique. The lemongrass emulsion fuel is prepared in the proportion of 94% of lemongrass oil, 5% of water, and 1% of surfactant span 80. The nanoparticles of cerium oxide were used with lemongrass oil (LGO) nano-emulsion in the measurement of 30 ppm. The four-stroke diesel engine execution, ignition, and the outflow extent were contrasted in the diesel and lemongrass oil (LGO) compared with the base diesel engine. The performance characteristic curves of lemongrass-cerium oxide nano-emulsion fuel show the increase in brake thermal efficiency of 17.21% when compared with the mineral diesel fuel. The emission characteristics of lemongrass-cerium oxide nano-emulsion fuel show a drop in hydrocarbon and carbon monoxide emission by 16.21% and 15.21%, respectively, when compared with base diesel fuel and also there is a decrease in oxides of nitrogen and smoke emission by 24.1% and 6.3%, respectively, when compared to mineral diesel fuel.